2 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



toward the latter end of the summer its presence in more or less 

 destructive numbers was evident throughout the entire grape belt. 

 By far the greater injury occurred, however, in those vineyards por- 

 tions of which have been continuously infested. With the general 

 increase of this pest throughout the Lake Erie Valley there has 

 developed a feeling of anxiety on the part of many vineyardists 

 and a general inquiry is being made as to the best means of holding 

 it in check. 



Heretofore the chief factors in the lack of success of the vineyard- 

 ist in his efforts to combat this pest have been that he has either 

 failed to recognize the most vulnerable stage in its life history or 

 else he has minimized its capacity for injury until this period has 

 passed, only to be filled with regrets later in the season when his 

 vines are swarming with the winged adults and the foliage is so 

 badly injured by them that it presents a brown and scorched appear- 

 ance which renders it functionless at a period when healthy leaves 

 are necessary to the plant for the purpose of elaborating the sugar 

 of the fruit and for the proper maturing of the new growth so that 

 it will withstand the severity of the winter and make a vigorous 

 growth in the following spring. If. however, the vineyardist will 

 acquaint himself with the habits and development of this pest there 

 is no doubt that he can combat it successfully when it is in the im- 

 mature stages, before its wings are fully developed, bv the thorough 

 application of a contact spray. 



CHARACTERISTICS AND HABITS OF THE GRAPE LEAFHOPPER, 



Before proceeding to discuss remedial measures, the primary object 

 of this paper, it may be well to consider briefly the characteristics, 

 habits, and life history of the grape leaf hopper, inasmuch as they 

 vary greatly from those of another very destructive pest of the 

 grapevine, namely, the grape rootworm. 



The grape leafhopper is a minute insect, less than one-eighth of an 

 inch long. The body and wings are of a light yellowish color, and the 

 wings entirely envelop the upper part of the abdomen in a roof like 

 covering when the insect is at rest. This j:>osition of the wings has 

 an important bearing on the killing effect of a contact spray. As the 

 hibernation period approaches, the more pronounced yellow marking 

 of the wings and body changes to an orange-red. which, however, 

 exists only during the winter months and disappears after the insect 

 has fed for a short time on the foliage of the vine during the follow- 

 ing spring. These winged forms are the mature or adult insects and 

 are the forms most familiar to the casual observer. The adults are 

 frequently found in large numbers leaping and flying actively among 

 the foliage of the vines during the early part of the grape-picking 

 season, in September and early October. Sometimes during bright, 



